GB542678A - Improvements in sorting apparatus - Google Patents

Abstract

542,678. Sorting solid materials; conveyers; thermionic relay circuits. JENNINGS, H. W. K. (California Cedar Products Co.). Aug. 12, 1940, No. 12901. [Class 117] [Also in Groups XXX and XL] Articles, such as pencil slats S, to be sorted by grade are carried past an inspection post on a conveyor 4 traversed longitudinally on a table 1 by pulleys 5. Underneath the table is a chain 7 carrying electric condensers 10 each associated with a slat and moving along with it. One plate ot eacn condenser is earthed through the chain; the other is insulated and carries an upwardly projecting contact finger. The operator wears a glove with metal thimbles on the fingers connected to a source which imparts to them definite and different potentials. As the slats pass the inspection post, the operator imparts to the associated condenser a potential corresponding to the grade of each slat by touching the plate with the appropriate thimble. At each of the selecting stations, represented by the collecting bins 16a, there is mounted a kick-off device consisting of a pivoted lever 19 held in the inoperative position by a spring and stop, and actuated by an electro-magnet 17 to discharge a slat. Each magnet is in a circuit, the elements of which are contained in a box 27 mounted under the table, and which includes a relay which may be an electronic device, such as a thyratron, the grid of which is electrically connected to a spring contact 25. As successive slats pass the selecting stations, the upstanding contacts on the associated condensers engage the spring contacts 25 and impart the corresponding potentials to the grids, which are biased to varying degrees; if the applied potential is sufficient to trigger the relay, the magnet circuit is completed and the corresponding slat kicked off by the lever li9 into a bin 16a. Slats that pass all the stations are delivered into a bin at the discharge end of the conveyer, where a spring contact 26, which is earthed, is also provided to discharge the condensers. One of the thimbles on the operator's glove is earthed to enable mistakes to be rectified by discharging an incorrectly charged condenser and re-charging it correctly. The circuit for energising the electromagnets, Fig. 5 (not shown), comprises a transformer the primary of which is connected to A.C. mains and the secondary of which includes a low voltage winding for heating the filament of a thyratron, and a high voltage winding for providing the potential between the filament and anode, and the adjustable grid bias.